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U.S. Genetic Evaluations
1. Lifetime Net Merit $
Lifetime Net Merit $ measures net profit over the lifetime of a bull's average daughter.
Traits and weightings in the Lifetime NM$2006 index:
| Production (23% PTA Fat & 23% PTA Protein) |
46% |
| Productive Life (PL) |
17% |
| Somatic Cell Score (SCS) |
-9% |
| Daughter Pregnancy Rate (DPR) |
9% |
| Calving Ease (SCE) (DCE) |
2% |
| Stillbirths (SSB) (DSB) |
4% |
| Udder Composite |
6% |
| Feet and Legs Composite (FLC) |
3% |
| Size Composite |
-4% |
2. Lifetime Net Merit $ Percentage Ranking
Net Merit $ ranking in the U.S. population.
3. Reliability (REL or R)
A measure of the amount of information in a trait. Reliability is expressed as a percentage,
ranging from 1 to 99. The closer the Reliability is to 99, the more reliable the proof.
4. Lifetime Cheese Merit $
Lifetime Cheese Merit $ was designed for producers who sell milk in a cheese market.
Protein has more value in the cheese market than it does in the standard component
pricing market. Milk receives a negative economic weight in the Cheese Merit index.
The Lifetime Cheese Merit index combines the same traits as the Lifetime Net Merit index.
5. Lifetime Fluid Merit $
Lifetime Fluid Merit $ combines the same traits as the Net Merit index with different
weightings. This index is useful for dairies paid solely for milk volume, as more emphasis
is placed on milk yield.
6. Daughters
The number of daughters included in the bull's milk proof.
7. Herds
The number of different herds a bull's daughters are located in (considering daughters
which are included in the bull's milk proof).
8. PTA Milk
PTA for milk production in pounds, reflecting the expected milk production of future
mature daughters.
9. PTA Fat Pounds
PTA for butterfat in pounds, reflecting the expected butterfat production of future
mature daughters.
10. PTA Fat Percent
Indicates the genetic variance of a bull's PTA for transmitting fat as being positive
or negative.
11. PTA Protein Pounds
PTA for protein production in pounds, comparing the expected production of future mature daughters.
12. PTA Protein Percent
Indicates the genetic variance of a bull's PTA for transmitting protein as being positive or negative.
13. PTA Productive Life
Productive Life is a measure of longevity, measured in months.
14. PTA Somatic Cell Score (SCS)
The PTA for SCS is used to improve mastitis resistance. Bulls with low PTA for SCS (less than 3.0)
are expected to have daughters with lower mastitis than bulls with high PTA for SCS (greater than 3.5).
15. PTA Type (PTAT)
PTA Type is an estimate of the genetic superiority for conformation that a bull will transmit to its
offspring. This is directly correlated with the final score of the bull's daughters, not the linear traits.
16. Udder Composite
Udder Composite is an index based on ability for udder improvement. Udder Composite includes
six linear traits, and the weighting for each trait reflects the trait's contribution to higher udder scores.
The traits and their weightings are:
| Udder Depth |
35% |
| Front Teat Placement |
5% |
| Fore Udder Attachment |
16% |
| Rear Udder Height |
16% |
| Rear Udder Width |
12% |
| Udder Cleft |
9% |
| Rear Teat Placement |
7% |
17. Feet and Legs Composite
Feet and Legs Composite is a measure of a bull's ability for foot and leg improvement. Weights for
the four traits in the composite are:
| Feet and Legs Score |
50% |
| Foot Angle |
24% |
| Rear Legs-Rear View |
18.5% |
| Rear Legs-Side View |
7.5% |
18. Body Composite
Body Size composite is calculated from the four linear traits; stature, strength, body depth
and rump width. The calculation is:
(.5 x Stature) + (.25 x Strength) + (.15 x Body Depth) + (.10 x Thurl Width)
Every 1 STA increase in body size equals a 24 pound increase in mature body weight. To put
this in perspective, daughters of bulls that sire large cows (large positive evaluations for body size, +3.00)
are expected to weight 144 pounds more than those that sire small cows (large negative evaluations for
body size, -3.00).
19. Dairy Capacity Composite
Dairy Composite is a measure of Dairy Form and Strength.
20. TPITM (Total Performance Index)
TPITM combines several traits into one index to rank sires on their ability to transmit a balance of
these traits. TPI is calculated by Holstein Association-USA. The traits and their values are:
| Fat & Protein |
45% |
| Productive Life |
10% |
| Somatic Cell Score |
5% |
| Udder Composite |
10% |
| Feet & Legs Composite |
5% |
| PTA Type |
13% |
| Dau Pregnancy Rate |
8% |
| Dau Calving Ease |
2% |
| Dairy Form |
1% |
| Dau Stillbirth |
1% |
21. Calving Ease
Sire Calving Ease: Percentage of Estimated Difficult Births in Heifers (EDBH) when they calve
for the first time. Using bulls 8% EDBH or less can be used to reduce stress on first-calf heifers.
Daughter Calving Ease: Tendency of daughters of a particular sire to have more (or fewer) problems
at calving than an average cow and to produce calves that are born more easily (or difficult) than
calves produced by an average cow.
22. Stillbirth
Service Sire Stillbirth: measures the tendency of calves from a particular service sire to be stillborn
more or less often. Daughter Stillbirth: measures the ability of a particular cow (daughter) to produce
live calves. Stillbirth is expressed as percent stillbirths, where stillborn calves are those scored as
dead at birth or born alive but died within 48 hours of birth.
23. Fertility
Sire Fertility: Sire Conception Rate (SCR) measures the fertility of a bull as a service sire. A new
method of calculating SCR was introduced in August 2008, replacing the old ERCR values. SCR
uses all services with a known outcome and adjusts for many effects that were not considered in ERCR.
SCR values are expressed as plus or minus deviation from the “average” sire. Average for bulls summarized
SCR will be expressed as a percent difference from an average of 0. Therefore a bull with a 1.5% SCR
expect 1.5% higher conception rate than a bull at 0.0%.
Composite Fertility Index
- Estimated Relative Conception Rate (ERCR)
Calculated by USDA-AIPL; first service, 70-day, non-return data; a three-year rolling average currently
includes 733,826 first services on 242 Select Sires with 300 or more first services per sire; includes
Eastern, Midwestern, Southeastern and Southwestern herds
- AgriTech Analytics Data (ATA)
Utilizes palpated pregnancy data; uses multiple services; is a continuous database with no time limit
on use of historic data; representing large herds located in the West; 487,915 total services on 133
Select Sires bulls with 10 or more services in 10 or more herds
- Relative Breeding Efficiency (RBE)
Calculated by Select Sires from data processed by Dairy Records Management Systems (DRMS);
multiple Service non-return rate (includes Program for Genetic Advancement™ (PGA™) herds); a
one year rolling herd average (therefore the data is current); contains 531 Select Sires with 200 or
more services for a total of 530,250 services; includes Eastern, Midwestern, Southeastern and
Southwestern herds
Daughter Pregnancy Rate (DPR): Percentage of non-pregnant cows that becomes pregnant
during each 21-day period. A DPR of ‘1’ implies that daughters from this bull are 1% more likely
to become pregnant during that estrus cycle than a bull with an evaluation at zero.
Linear Type Traits
Genetic evaluations for the 18 linear type traits are expressed as Standard Transmitting Abilities (STAs). Standardized values are used because each trait has a different average PTA, and the PTA ranges
vary within traits. STAs simplify interpreting the linear genetic evaluations. As a result, all linear traits
have an average of 0. The range of STA values is generally 6 STA units. Both extremes for each trait
are approximately 3 STA units from the average.
Interbull and Interbull-MACE
If a bull has daughters in two or more countries he receives an Interbull proof. Interbull allows
comparisons of bulls who were sampled in different countries. Interbull-MACE (Multiple Trait Across
Country Evaluation) is used for international type evaluations. The Interbull proof listed is on the
U.S.A. base.
Genetic Base
The genetic base for the evaluations is PTA 05, representing the average of cows born in 2000.
Breeding Program Tools
aAa
Triple A or aAa is used by breeders as a common-sense mating program to breed more profitable
cows, by using six numbers all of which have a definition. The bulls are coded the way they are
made and the females given the numbers they need (to improve). The numbers corresponding
to the bulls transmitting strengths are then matched to the cows weaknesses to make a
"perfect combination" e.g. a 165 bull is mated onto a 165 cow.
The number codes have one word descriptions but each code has a number of traits that
correlate highly with that number. The number definitions are as follows:
| 1. |
Dairy - ample will to milk, refined head, tailhead and hocks, long neck, sharp hooks and pin bones. |
| 2. |
Tall - long head, long legs, long back strong pasterns, high udder. |
| 3. |
Open - open angular ribs, wide thurls and pins, open hocks, ample room for the udder, calving ease number. |
| 4. |
Strong - large head, wide chest, large capacity, plenty of room for the lungs, strong healthy legs. |
| 5. |
Smooth - big cow on short legs (Blackrose type) good width and capacity, easy managed cows. |
| 6. |
Style - The fancy kind, all parts blending nicely together, strong loins level rumps generally
have short rounded feet. |
DMS: Dairy Mating Service
DMS is a tool used by dairymen to create a high producing, well-balanced cow with longevity. It is a mating service whose goal is to produce a cow that effectively and efficiently meets the goals of the dairyman. With only three major parts of the cow being analyzed, this can be accomplished in one generation and generations to come.
The three major parts analyzed are:
| 1. |
The front end – being the health of the cow |
| 2. |
Udder and frame – being the production of the cow |
| 3. |
The rear end – being the reproduction of the cow |
Each cow is coded using three of the six codes depending upon which parts of the cow need correcting.
The codes used are as follows:
1-strong 2- smooth 3-style 4-dairy 5-tall 6 –flat bone
Cows are coded to improve their weakest traits. Bulls are coded for their ability to transmit their strengths. All the bulls at the major A.I. organizations in the United States and Canada are analyzed by a professional DMS analyzer.
DMS is a totally independent mating program designed to match up not only the traits in a cow you would like to correct, but also looks at ancestry that transmits certain traits from the cow and the bull you are using.
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